Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
  • B01D61/362—Pervaporation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
  • B01D67/0002—Organic membrane manufacture
  • B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
  • B01D67/0018—Thermally induced processes [TIPS]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
  • B01D71/38—Polyalkenylalcohols; Polyalkenylesters; Polyalkenylethers; Polyalkenylaldehydes; Polyalkenylketones; Polyalkenylacetals; Polyalkenylketals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
  • B01D71/38—Polyalkenylalcohols; Polyalkenylesters; Polyalkenylethers; Polyalkenylaldehydes; Polyalkenylketones; Polyalkenylacetals; Polyalkenylketals
  • B01D71/381—Polyvinylalcohol
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
  • B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/08—Specific temperatures applied
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2323/00—Details relating to membrane preparation
  • B01D2323/08—Specific temperatures applied
  • B01D2323/081—Heating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/02—Details relating to pores or porosity of the membranes
  • B01D2325/022—Asymmetric membranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2325/00—Details relating to properties of membranes
  • B01D2325/02—Details relating to pores or porosity of the membranes
  • B01D2325/027—Nonporous membranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
  • B01D71/06—Organic material
  • B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters

Definitions

• the invention relates to a membrane having a pore-free separating layer, including a polymer mixture for separating simple alcohols and water from their mixtures with other organic fluids by means of pervaporation or vapor permeation, as well as to the use and to a method of manufacturing such a membrane in accordance with the preamble of the independent claim of the respective category.
• the invention thus relates, in addition to a new composite polymer membrane as such, in particular to a method of manufacturing composite polymer membranes and to their use for separating simple alcohols from their mixtures with organic liquids in accordance with the methods of pervaporation and vapor permeation. Furthermore, these membranes can also be used for the simultaneous separation of water and simple alcohols from their mixtures with organic liquids in accordance with the aforesaid methods.
• membranes are e.g. described which are suitable to separate water from its mixtures with organic liquids by pervaporation. It is known that the liquid mixture is brought into contact with the one side of the polymer membrane, whereas on the other side a vacuum is applied or an inert gas flow is conducted past. One or more components of the liquid mixture can permeate through the polymer membrane. Components which permeate less easily remain in the liquid phase and are enriched with it.
• the separating layer of the membrane is in practice often composed of cross-linked polyvinyl alcohol (PVA) which is applied to a porous support layer of a material which is suitable for an ultrafiltration membrane. Due to the desired thermal stability and chemical resistance, porous support layers of polyacrylonitrile (PAN), polysulfone (PSU) and of the hydrolyzed or saponified cellulose acetates are preferred.
• PAN polyacrylonitrile
• PSU polysulfone
• the porous support layer is usually applied to a fleece or to a woven cloth as a carrier layer.
• DE 4 234 521 describes a membrane having a separating layer which is manufactured by plasma polymerization and which is suitable for separating methanol from its mixtures with e.g. MTBE and DMC.
• a method is described in U.S. Pat. No. 4,960,519 for separating methanol from its mixtures with compounds containing oxygen; the latter include organic ethers, aldehydes, ketones and esters.
• the membrane is composed of a non-porous separating layer made from a mixture of PVA and PVA polyacrylic acid. This separating layer is applied to a support layer of PAN.
• EP 0 674 940 describes the use of a membrane for separating simple alcohols, in particular ethanol, from mixtures with other organic liquids in accordance with the methods of pervaporation and vapor permeation.
• the separating layer of the membrane is composed of a film of a homopolymer, copolymer or terpolymer.
• Poly DMAEMA Poly N—N-dimethylaminoethyl methacrylate (poly DMAEMA) is used as the homopolymer; a copolymer from DMAEMA and N-vinyl pyrrolidone (NVP) or from DMAEMA and N-vinyl caprolactam (NVCL) is used as the copolymer; and a terpolymer from DMAEMA, NVP and NVCL is used as the terpolymer.
• NVP N-vinyl pyrrolidone
• NVCL N-vinyl caprolactam
• a terpolymer from DMAEMA, NVP and NVCL is used as the terpolymer.
• Such polymers are particularly preferred in which the nitrogen atom of the amine group of the DMAEMA is present as a quaternary ammonium.
• Preferred quaternary agents are dimethyl sulfate and, diethyl sulfate as well as monochloromethane and monochloroethane, monoiodide methane and monobromomethane and monoiodide ethane and monobromoethane.
• the homopolymer, copolymer or terpolymer is dissolved in water, ethanol or their mixtures and is applied to a porous support layer.
• the vaporization of the solvent takes place at 50° C.-100° C.
• the film is subsequently cross-linked by heat treatment, particularly preferably at temperatures between 120° C.-160° C.
• the polymer film as stated becomes insoluble in water and ethanol by the thermal treatment.
• membranes known from the prior art for separating light alcohols from organic mixtures is, however, greatly restricted, above all in the presence of water at higher temperatures.
• the membrane then swells up so much in part in a plurality of organic solvents such as ethers, ketones and multivalent alcohols that it can be destroyed.
• Organic solvents such as ethers, ketones and multivalent alcohols that it can be destroyed.
• Membranes having solid ions change their behavior when they come into contact with water or salts.
• the object of the invention to provide a membrane for separating simple alcohols from organic mixtures as well as to provide the use of and to provide a method of manufacturing such a membrane which avoids the disadvantages known from the prior art.
• the membrane should above all, but not only, also be able to be used reliably in the presence of water and at higher temperatures and should in this respect, contrary to the prior art, not swell up so much that it can be destroyed in organic solvents such as ethers, ketones and multivalent alcohols.
• the membrane should simultaneously show good selectivities, flows and stability even at higher water concentrations and higher temperatures and should show a high selectivity and simultaneously a high flow for alcohols in the absence of water.
• the invention thus relates to a membrane having a pore-free separating layer including a polymer mixture for separating simple alcohols and water from their mixtures with other organic fluids by means of pervaporation or vapor permeation.
• the polymer mixture is composed of at least two polymer components which are taken from the group of polymer components which includes the following polymer components: Polyvinyl alcohol, other polymers such as poly N—N-dimethylaminoethyl methacrylate (poly DMAEMA), a copolymer of DMAEMA and N-vinyl pyrrolidone (NVP) or of DMAEMA and N-vinyl caprolactam (NVCL), a terpolymer of DMAEMA, NVP and NVCL or of vinyl acetate ethylene vinyl chloride or from vinyl chloride ethylene acrylic ester or from vinyl acetate vinyl chloride acrylic ester.
• poly DMAEMA poly N—N-dimethylaminoethyl methacrylate
• NVP N-vin
• membranes can be manufactured whose use in accordance with the present invention for separating simple alcohols or simple alcohols and water simultaneously shows good selectivities, flows and stabilities even at higher water concentrations and higher temperatures.
• the selectivity and flow for alcohols are also very high in the absence of water.
• the polymer solution is applied to a porous sub-structure having an asymmetrical pore structure and the porous sub-structure lies in turn on a carrier layer.
• a membrane in accordance with the invention is used for separating simple alcohols and water from their mixtures with other organic fluids by means of pervaporation or vapor permeation.
• the alcohol permeating through the membrane is preferably a methanol, an ethanol or a propanol and the substance held back by the membrane is specifically an aliphatic or aromatic hydrocarbon, an ether, ketone, ester or a higher alcohol or a mixture of components from this group.
• the invention further relates to a method of manufacturing a membrane having a pore-free separating layer including a polymer mixture for separating simple alcohols and water from their mixtures with other organic fluids by means of pervaporation or vapor permeation.
• the polymer mixture is manufactured from two polymer components which are taken from the group of polymer components including: Polyvinyl alcohol, other polymers such as poly N—N-dimethylaminoethyl methacrylate (poly DMAEMA), a copolymer of DMAEMA and N-vinyl pyrrolidone (NVP) or of DMAEMA and N-vinyl caprolactam (NVCL), a terpolymer of DMAE, NVP and NVCL or of vinyl acetate ethylene vinyl chloride or from vinyl chloride ethylene acrylic ester or from vinyl acetate vinyl chloride acrylic ester.
• poly DMAEMA poly N—N-dimethylaminoethyl methacrylate
• NVP N-vinyl
• a solvent of the homopolymers, copolymers or terpolymers and polyvinyl alcohol in water, ethanol or an ethanol-water mixture is used for manufacturing the separating layer.
• the polymer solution is preferably applied to a porous sub-structure having an asymmetrical pore structure and the porous sub-structure is in turn applied to a carrier layer.
• the solvent can be vaporized and the membrane can be subjected to a heat treatment.
• the heat treatment takes place at a temperature between 100° C. and 200° C., preferably at a temperature from 130° C. to 180° C.
• the heat treatment is carried out during a time period from 1 min to 60 min, preferably during a time period from 5 min to 30 min.
• the heat treatment is particularly preferably carried out in one or more stages, particularly preferably in two stages.
• the temperature of a following stage can in this respect, for example, be higher than the temperature of a preceding stage.
• the separating layer of the membranes used in accordance with the present invention is composed of a polymer blend film produced from at least two polymers.
• the polymers can be homopolymers, copolymers and terpolymers.
• Polyvinyl alcohol and poly-N—N-dimethylaminoethyl methacrylate (poly DMAEMA) are used as the homopolymer;
• a copolymer of DMAEMA and N-vinyl pyrrolidone (NVP) or of DMAEMA and N-vinyl caprolactam (NVCL) is used as the copolymer;
• a terpolymer of DMAEMA, NVP and NVCL, of vinyl acetate ethylene vinyl chloride, of vinyl chloride ethylene acrylic ester or of vinyl acetate vinyl chloride acrylic ester is used as the terpolymer.
• the content of polyvinyl alcohol can amount to between 1% by weight to 90% by weight, preferably 3% by weight to 80% by weight; the content of other polymers can amount to between 10% by weight to 99% by weight, preferably 20% by weight to 97% by weight.
• Polyvinyl alcohol is admixed as a watery solution; the cross-linking takes place by esterification with dicarboxylic acids, preferably those which additionally contain hydroxyl groups and/or keto groups, by etherification under the catalytic effect of the acids, by acetalization by means of aldehydes or dialdehydes or by a combined application of these methods.
• the homopolymers, copolymers or terpolymers are dissolved in water, ethanol or a mixture of water-ethanol.
• concentrations between 2% by weight and 60% by weight (in dependence on the molecular weight) are preferred; concentrations between 3% by weight and 20% by weight are particularly preferred.
• the solution is applied to a substrate by means of a method known per se to the skilled person.
• the pore-free separating layer is preferably located on a porous support layer. Applying the polymer film as a separating layer to a composite structure has proved to be particularly advantageous.
• it is composed of a carrier layer, e.g.
• a porous structure having an asymmetrical pore structure preferably made of polyacrylonitrile, polysulfone, polyvinylidene fluoride, polyamide, polyetherimide or other polymers is located on this carrier layer.
• a pore-free, dense polymer film is formed whose thickness is dependent on the concentration and on the application method.
• Polymer films between 0.5 ⁇ m and 20 ⁇ m thickness are preferred; polymer films from 1 ⁇ m to 6 ⁇ m are particularly preferred.
• the vaporization of the solvent takes place at 60° C. to 160° C.
• the film is subsequently cross-linked through heat treatment, preferably at temperatures from 100° C. to 200° C., particularly preferably 130° C. to 180° C., in times between 1 min to 60 min. It has proved to be advantageous to carry out the heat treatment in a plurality of stages, wherein a two-stage procedure is preferred, e.g. at 100° C. to 140° C. for 1 min to 6 min, then in a second stage at 150° C. to 180° C. for 6 min to 30 min.
• a solution of 6% polymer mixture in water is applied with an application roller onto a porous support layer of polyacrylonitrile (PAN) which has an asymmetrical pore structure and which is applied to a carrier layer of a polyester fleece.
• PAN polyacrylonitrile
• the polymer mixture is composed of polymers in a ratio of 70% by weight of a copolymer of vinyl pyrrolidone and dimethylaminoethyl methacrylate and a 30% by weight portion of polyvinyl alcohol and is applied using an application roller.
• the solvent is evaporated at 125° C. in 6 min.
• the membrane is then thermally treated at 150° C. for 20 min. and in a second step further thermally cross-linked at 170° C. for 10 min.
• the separating layer of the finished membrane has a thickness of approximately 3 ⁇ m.
• it is tested at 80° C. with an inflow mixture of 40% methanol and 60% tetrahydrofuran.
• the permeate contains 72% by weight methanol, the methanol flow amounts to 8 kg/m 2 h at a pressure on the permeate side of 20 mbar.
• the permeate is condensed by cooling with a mixture of dry ice and ethanol.
• a 5% watery polymer mixture composed of a 90% by weight portion of a quaternary copolymer of vinyl pyrrolidone and dimethylaminoethyl methacrylate and a 10% by weight portion of a copolymer of vinyl acetate, ethylene and vinyl chloride (VAC/E/VC), is applied to the same sub-structure as in Example 1 using an application roller.
• the evaporation of the solvent took place after 7 min at 130° C.; the membrane is then heat treated at 150° C. for 21 min.
• a pervaporization trial with an inflow mixture of 21% by weight ethanol and 79% by weight ethyl-t-butylether (ETBE) at 62° C. produced 94% by weight ethanol in the permeate at 1.35 kg/m 2 h ethanol flow at a pressure on the permeate side of 13 mbar.
• the permeate is condensed by cooling with a mixture of dry ice and ethanol.
• a 4.5% watery polymer mixture composed of a 30% by weight portion of a copolymer of vinyl pyrrolidone and dimethylaminoethyl methacrylate and of a 70% by weight portion of polyvinyl alcohol, is applied to the same sub-structure as in Example 1 using an application roller.
• the evaporation of the solvent takes place after 6 min at 150° C.; the membrane is then post cross-linked at 145° C. for 24 min.
• a 4.5% watery polymer mixture composed of a 60% by weight portion of a copolymer of vinyl pyrrolidone and dimethylaminoethyl methacrylate and of a 40% by weight portion of polyvinyl alcohol, is applied to the same sub-structure as in Example 1 using an application roller.
• the evaporation of the solvent took place after 6 min at 150° C., the membrane is then thermally treated at 150° for 15 min and is further cross-linked in a second step at 180° C. for 10 min.
• a pervaporation trial with an inflow mixture of 30% by weight methanol and 70% by weight acetone at 60° C. produced 70% by weight methanol in the permeate at 2.5 kg/m 2 h methanol flow at a pressure on the permeate side of 10 mbar.
• the permeate is condensed by cooling with a mixture of dry ice and ethanol.
• a 5% watery polymer mixture composed of a 90% by weight portion of a quaternary copolymer of vinyl pyrrolidone and dimethylaminoethyl methacrylate and a 7% by weight portion of a copolymer of vinyl acetate, ethylene and vinyl chloride (VAC/E/VC) and a 3% by weight portion of polyvinyl alcohol, is applied to the same sub-structure as in Example 1 using an application roller. The evaporation of the solvent took place after 7 min at 130° C.; the membrane is then heat treated at 150° C. for 21 min.
• a pervaporization trial with an inflow mixture of 21% by weight ethanol and 79& by weight ethyl-t-butylether (ETBE) at 62° VC produced 97% by weight ethanol in the permeate at 0.65 kg/m 2 h ethanol flow at a pressure on the permeate side of 13 mbar.
• the permeate is condensed by cooling with a mixture of dry ice and ethanol.

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• Chemical & Material Sciences (AREA)
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• Engineering & Computer Science (AREA)
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• Thermal Sciences (AREA)
• Dispersion Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 2011
  • 2011-07-06 US US13/825,313 patent/US9873091B2/en active Active
  • 2011-07-06 CN CN2011800450277A patent/CN103249475A/zh active Pending
  • 2011-07-06 CA CA2811533A patent/CA2811533C/en active Active
  • 2011-07-06 EP EP11729428.0A patent/EP2618918B1/de active Active
  • 2011-07-06 JP JP2013528562A patent/JP5851508B2/ja not_active Expired - Fee Related
  • 2011-07-06 BR BR112013003432-7A patent/BR112013003432B1/pt active IP Right Grant
  • 2011-07-06 WO PCT/EP2011/061405 patent/WO2012038110A1/de active Application Filing
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• 2012
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